Mars rover Spirit has tenaciously swept, scraped, and squeezed secrets from the forbidding surface of Mars for 6 years. If Spirit can make it through to spring, the feisty robot will prove it's still in the game--by solving the mysteries of the Martian core.

While the Mars rovers Spirit and Opportunity do not carry a microphone, these audio excerpts represent the journeys the Mars rovers have made while driving across the plains, mountains and craters of Mars during the last six years.

Design a Sport for Mars and Win a Trip to NASA's Jet Propulsion LaboratoryThe Kids Science Challenge, with support from NASA's Imagine Mars Project, is asking students in grades 3 through 6 to consider what sports might be played by members of the first martian community.